To prevent leakage of information displayed on an image display device without imposing a special load on a user.

A drawing management system 1 includes: a drawing terminal 10; a server 20 having an image data storage part 22 to store image data drawn in the drawing terminal; and a network 30 connecting the drawing terminal to the server. The drawing terminal includes: an identification information reading part 11 for reading identification information stored in a noncontact information storage medium C; an input receiving part 12 for receiving an image input from the user; an image display part 13 for displaying the image data inputted from the input receiving part; and a control part 17 for controlling the whole device. The control part deletes the displaying in the image display part when the noncontact information storage medium is detected to exist out of a communication permission range with the identification information reading part.